The Operation for Tuberculosis of the Central Nervous System in Children
85% of children with TB meningitis: Hydrocephalus, either communicating (more common) or obstructive, is one of the commonest complications of TB meningitis. It occurs in up to 85% of children with the disease, in whom it is more severe than in adults.
Shunt vs. EVD: Patients with enlarged ventricles and a GCS >8 and <14 are best served with an early shunt procedure. For patients with a GCS >3 and <8, an EVD can be placed and the response re-assessed. Those who improve within 48 hours are good candidates for shunts, whereas those for whom the EVD fails to be effective are unlikely to benefit from a shunt and are managed conservatively (25).
Shunt vs. ETV: Ventriculoperitoneal shunting is the procedure of choice if the duration of illness is less than 4 weeks, whereas ETV or ventriculoperitoneal shunting can be considered if the duration is greater than 4 weeks.
Shunt technique: Ventriculoatrial shunts were the initial choice for shunt procedures. There was a shift to ventriculoperitoneal shunts in the early 1980s, and since then ventriculoperitoneal shunt has remained the shunt procedure of choice for patients with TB meningitis and hydrocephalus (25).The technique for shunt surgery does not differ from that used for hydrocephalus from any other cause.
ETV: In patients with TB meningitis, the floor of the third ventricle is frequently thick and the subarachnoid space is also likely to be obliterated by exudates, thereby making it difficult to recognize anatomical landmarks. In this situation it might be more prudent to abandon the procedure than risk injury to the basilar artery and its branches. Outcome was better in those patients with longer duration of symptoms and receiving antituberculous treatment for 4 weeks prior to ETV than in those operated on earlier. ETV could also be considered for patients who have shunt failure, as it might be a better option than shunt revision in these patients (50).
Surgical indications – neurological symptoms or nonresolution: Rarely, tuberculomas coalesce and liquefy to cause cerebral TB abscess, which may necessitate surgery. TB abscess occurs in only 4–8% of patients with CNS TB who do not have HIV infection but in 20% of patients with CNS TB who do have HIV infection (24). Spinal TB associated with paraparesis responds well to medical treatment (which may include corticosteroids) if the MRI shows relatively preserved cord size and edema with predominantly fluid compression. Patients with extradural compression by a tuberculoma or abscess, but with little fluid component compressing or constricting the cord, probably need early surgical decompression (3, 22, 26, 44, 45).
Pretreatment with antibiotics: Early anti-TB therapy must be considered in all cases of suspected TB abscess even before surgery to reduce the risk of postoperative meningitis. Early surgical drainage and chemotherapy are considered the most appropriate treatment for TB abscess (24).
Treatment options: An open surgical excision is typically used for large, superficial, or multiloculated cerebellar lesions. For smaller or deeper lesions a free-hand or stereotactically guided aspiration via a bur hole or small craniotomy can be considered.
70% of aspirated lesions require repeat drainage: When managed with bur hole or stereotactic aspiration, abscesses require frequent, repeated drainage (22).
Surgical goal – reduce mass: The aim of surgical management of TB abscess is to reduce the size of the space-occupying lesion to diminish ICP and eradicate the pathogen. This should improve the efficacy of the anti-TB therapy. Surgery also helps to establish the diagnosis in cases that have not responded to medical treatment (3, 24, 26, 51).
Imaging: Typically, imaging is done 3 months after initiation of treatment and on a regular annual basis thereafter. Imaging is done acutely when there is concern about treatment failure and disease relapse or drug noncompliance.